title: Unipolar signal modification as a guide for lesion creation during radiofrequency application in the left atrium: prospective study in humans in the setting of paroxysmal atrial fibrillation catheter ablation.
abstract: BACKGROUND
  In patients treated for paroxysmal atrial fibrillation, the pulmonary vein (PV) reconnection rate is substantial and may be related to the lack of transmurality achievement while performing PV isolation (PVI). It has been experimentally demonstrated that positive unipolar atrial electrogram completion, when applying radiofrequency energy, was associated with transmural lesions. In this regard, we seek to determine whether the unipolar signal modification may be an appropriate end point for point-by-point radiofrequency application and find out whether it could improve the paroxysmal atrial fibrillation ablation results in humans.
  
  
  RESULTS
  Fifty consecutive patients (61±8 years old, 41 men) with paroxysmal atrial fibrillation underwent PVI using Carto and Lasso. Each radiofrequency application lasted until development of a completely positive unipolar electrogram. Fifty patients (63±9 years old, 40 men), who previously underwent PVI following the standard approach of our institution, corresponded to the control group. All PVs were isolated in all patients of both groups. However, the procedural and ablation times were significantly lower in the unipolar group compared with those of the control group, whereas the PV reconnection rate, after 30 minutes of waiting time, was not significantly different. Overall, 21±4 months after 1 PVI session, the sinus rhythm maintenance rate without antiarrhythmic drugs was significantly higher (P=0.027) in the unipolar group (88%) compared with that of the control group (70%).
  
  
  CONCLUSIONS
  Unipolar signal modification is a useful end point for radiofrequency energy delivery in patients with paroxysmal atrial fibrillation who undergo PVI and leads to a substantial midterm sinus rhythm maintenance rate.
authors.affiliation: Service de Cardiologie, Hôpital Privé Les Franciscaines, Nîmes, France.
authors.forename: Agustín
authors.initials: A
authors.lastname: Bortone
authors.forename: Anthony
authors.initials: A
authors.lastname: Appetiti
authors.forename: Abdeslam
authors.initials: A
authors.lastname: Bouzeman
authors.forename: Eric
authors.initials: E
authors.lastname: Maupas
authors.forename: Vlad
authors.initials: V
authors.lastname: Ciobotaru
authors.forename: Jean-Marc
authors.initials: JM
authors.lastname: Boulenc
authors.forename: Pénélope
authors.initials: P
authors.lastname: Pujadas-Berthault
authors.forename: Philippe
authors.initials: P
authors.lastname: Rioux
mesh_terms: D000368:Aged; D017115:Catheter Ablation / Q000379:methods*; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D006325:Heart Atria; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011667:Pulmonary Veins / Q000601:surgery; D013614:Tachycardia, Paroxysmal / Q000601:surgery
keywords: atrial fibrillation; catheter ablation; radiofrequency